The effect of segmental bronchoprovocation with allergen on airway lymphocyte function

Am J Respir Crit Care Med. 1997 Nov;156(5):1421-8. doi: 10.1164/ajrccm.156.5.9703054.


We hypothesized that allergen-induced airway eosinophilia is linked to activation or recruitment of T cells in the airway and generation of interleukin-5 (IL-5). To evaluate this hypothesis, we performed bronchoscopy with segmental antigen bronchoprovocation in 12 atopic subjects. Bronchoalveolar lavage (BAL) was done 5 min and 48 h after challenge with saline or antigen. Airway cells were isolated and then stimulated ex vivo with a T-cell mitogen, phytohemagglutinin (PHA), and cytokine release was determined. Cells retrieved from the saline-challenged segment secreted principally interferon-gamma (IFN-gamma) and IL-2. In contrast, cells obtained 48 h after allergen challenge secreted high levels of IL-5 and small but increased amounts of IL-4, IL-10, and granulocyte-macrophage colony-stimulating factor (GM-CSF). Although CD4+ T cells were a major source of IL-5, there were no significant changes in the relative proportion of CD4+ cells in response to bronchoprovocation. Additionally, ex vivo secretion of IL-5 by airway cells correlated closely with amounts of IL-5 and eosinophils present in the bronchoalveolar lavage fluid (BALF). These observations suggest that following exposure to allergen, airway T cells are functionally but not phenotypically different from resident airway T cells, and that T cells within the airway contribute to eosinophilic airway inflammation through the secretion of IL-5.

Publication types

  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Adult
  • Allergens*
  • Bronchi / cytology
  • Bronchi / immunology*
  • Bronchial Provocation Tests*
  • Bronchoalveolar Lavage Fluid / cytology
  • CD4 Lymphocyte Count
  • Enzyme-Linked Immunosorbent Assay
  • Female
  • Flow Cytometry
  • Granulocyte-Macrophage Colony-Stimulating Factor / metabolism
  • Histamine Release
  • Humans
  • Interferon-gamma / metabolism
  • Interleukin-5 / metabolism
  • Interleukins / metabolism
  • Lymphocyte Activation
  • Male
  • Phytohemagglutinins
  • T-Lymphocyte Subsets
  • T-Lymphocytes / immunology*


  • Allergens
  • Interleukin-5
  • Interleukins
  • Phytohemagglutinins
  • Interferon-gamma
  • Granulocyte-Macrophage Colony-Stimulating Factor